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Biomedical subjects

A Young

Publications and source records attributed to A Young.

At least 181 records · Page 10Linked to original sources
PubMed1995

Effects of resistance training on strength, power, and selected functional abilities of women aged 75 and older.

OBJECTIVE: To determine the effects of 12 weeks of progressive resistance strength training on the isometric strength, explosive power, and selected functional abilities of healthy women aged 75 and over. DESIGN: Subjects were matched for age and habitual physical activity and then randomly assigned into either a control or an exercise group. SETTING: The Muscle Function Laboratory, Royal Free Hospital School of Medicine, London. PARTICIPANTS: Fifty-two healthy women were recruited through local and national newspapers. Five dropped out before and seven (4 exercisers and 3 controls) during the study. Pre- and posttraining measurements were obtained from 20 exercisers (median age 79.5, range 76 to 93 years) and 20 controls (median age 79.5, range 75 to 90 years). INTERVENTIONS: Training comprised one supervised session (1 hour) at the Medical School and two unsupervised home sessions (supported by an exercise tape and booklet) per week for 12 weeks. The training stimulus was three sets of four to eight repetitions of each exercise, using rice bags (1-1.5 kg) or elastic tubing for resistance. The exercises were intended specifically to strengthen the muscles considered relevant for the functional tasks, but were not to mimic the functional measurements. No intervention was prescribed for the controls. MEASUREMENTS: Pre- and posttraining measurements were made for isometric knee extensor strength (IKES), isometric elbow flexor strength (IEFS), handgrip strength (HGS), leg extensor power (LEP), and anthropometric indices (Body impedance analysis, arm muscle circumference, and body weight). Functional ability tests were chair rise, kneel rise, rise from lying on the floor, 118-m self-paced corridor walk, stair climbing, functional reach, stepping up, stepping down, and lifting weights onto a shelf. Pre- and posttraining comparisons were made using analysis of variance or analysis of covariance (using weight as a covariate) for normally distributed continuous data and one-sided Fishers exact test (2 x 2 table) for discontinuous data. RESULTS: Improvements in IKES (mean change 27%, P = .03), IEFS (22%, P = .05), HGS (4%, P = .05), LEP/kg (18%, P = .05) were associated with training, but the improvement in LEP (18%, P = .11) did not reach statistical significance. There was an association between training and a reduction in normal pace kneel rise time (median change 21%, P = .02) and a small improvement in step up height (median 5%, P = .005). The other functional tests did not improve. CONCLUSIONS: Progressive resistance exercise can produce substantial increases in muscle strength and in power standardized for body weight in healthy, very old women. However, isolated increases in strength and LEP/kg may confer only limited functional benefit in healthy, independent, very old women.

Activities of Daily Living↗
PubMed1995

Relationship between colonial morphology and adherence of Streptococcus pneumoniae.

Phase variants in colonial opacity of pneumococci differ in the ability to colonize the nasopharynx of infant rats. To explain this observation at a cellular level, we compared the ability of opacity variants to adhere to buccal epithelial cells, type II pneumocytes, or vascular endothelial cells and to the glycoconjugates that represent the cognate receptors at each of these sites. The transparent phenotype was associated with enhanced adherence to buccal cells (approximately 100%) and their receptor relative to that of the opaque variants. Only modest differences in adherence (< 45%) were demonstrated to resting lung and vascular cells. In contrast, adherence of transparent variants increased by 90% to lung cells stimulated with interleukin-1 and by 130% to endothelial cells stimulated with tumor necrosis factor. In contrast, cytokine stimulation did not influence the adherence of opaque pneumococci. This difference correlated with the unique ability of transparent variants to adhere to immobilized GlcNAc and to cells bearing transfected platelet-activating factor receptors. These results suggest that the mechanism of enhanced colonization of the nasopharynx in vivo by transparent as compared with opaque phase variants involves a greater ability to adhere to both GlcNAc beta 1-3Gal on buccal epithelial cells and GlcNAc and PAF receptors on cytokine-activated, as opposed to resting, lung and endovascular cells.

Bacterial Adhesion↗
PubMed1995

Inhibition of leukocyte-endothelial cell interactions and inflammation by peptides from a bacterial adhesin which mimic coagulation factor X.

Factor X (factor ten) of the coagulation cascade binds to the integrin CD11b/CD18 during inflammation, initiating procoagulant activity on the surface of leukocytes (Altieri, D.C., O.R. Etingin, D.S. Fair, T.K. Brunk, J.E. Geltosky, D.P. Hajjar, and T. S. Edgington. 1991. Science [Wash.DC]. 254:1200-1202). Filamentous hemagglutinin (FHA), an adhesin of Bordetella pertussis also binds to the CD11b/CD18 integrin (Relman D., E. Tuomanen, S. Falkow, D.T. Golenbock, K. Saukkonen, and S.D. Wright. 1990. Cell. 61:1375-1382). FHA and the CD11b/CD18 binding loops of Factor X share amino acid sequence similarity. FHA peptides similar to Factor X binding loops inhibited 125I-Factor X binding to human neutrophils and prolonged clotting time. In addition, ETKEVDG and its Factor X analogue prevented transendothelial migration of leukocytes in vitro and reduced leukocytosis and blood brain barrier disruption in vivo. Interference with leukocyte migration by a coagulation-based peptide suggests a novel strategy for antiinflammatory therapy.

Adhesins, Bacterial↗
PubMed1995

EMG-responses to sudden onset free fall.

Recordings of axial and limb muscles in reaction to a free fall induced startle were performed in subjects while they were lying on a tilting couch with their eyes closed. Young normals (n = 24, aged 31.1 +/- 6.6 years) showed an activation sequence consisting of sternomastoid (N.XI: 57 ms), abdominal muscles (T10: 65 ms), quadriceps (L3: 75 ms) and deltoid (C5: 78 ms) and tibialis anterior (L4: 80 ms). The sequence of activation is not compatible with the current hypothesis of the startle being produced by a single volley spreading rostrally and caudally from the lower brainstem. Instead it is suggested that the startle is a patterned response organized by a putative reticular generator capable of spatio-temporal sequencing. Two avestibular patients had responses at mildly delayed latencies, showing that these can be elicited by non-vestibular inputs. Similar testing of 11 subjects aged 70-80 years showed a latency delay of ca. 26% in the EMG response but a similar activation sequence. The amount of delay in the elderly can only partially be attributed to age-dependent motor conduction slowing and suggests a prolongation of central processing time. In patients with advanced stages of akinetic-rigid syndromes abnormalities were seen in cases with an involvement of the brainstem reticular formation.

Accidental Falls↗
PubMed1995

Merger or murder?

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMed1995

Short-term outcomes in recent-onset rheumatoid arthritis.

Comparing outcomes of different therapeutic interventions is a vital part of progress in rheumatology, and considerable advances have been made in recent years toward consensus in outcome assessment. The conflicting results of longitudinal and cross-sectional studies of rheumatoid arthritis (RA) have been due, at least in part, to variable study designs. The few reports of prospective studies of recent-onset RA have been limited by the paucity of numbers at follow-up. Information on outcome and prognostic factors in RA requires prospective studies on large numbers of patients recruited from an early stage. The practising clinician needs easily applied prognostic factors for the effective management of patients with RA. Predicting erosive disease has been more successful than predicting functional outcome, but neither, as yet, have the accuracy required in early disease for the use of single or combined powerful, and potentially more toxic, second-line (disease-modifying) therapies. The Early Rheumatoid Arthritis Study (ERAS) was formed to study these aspects in more detail with large numbers of patients. Initial findings have shown that 15% of patients went into sustained clinical remission early, response to the first disease-controlling drug was satisfactory in 70% of patients and functional measures at presentation were by far the most predictive variables for physical disability at 3 yr.

Arthritis, Rheumatoid↗
PubMed1995

The cultural context of anxiety disorders.

About a century ago, George Crile, a surgeon and experimental physiologist, suggested that the meaning of pain could be discovered in the context of evolution. Pain is a signal of a physical injury that would be otherwise ignored by the individual, a form of ignorance that would ultimately have mortal consequences. Crile believed that pain has a second purpose, that has important implications for how psychiatry now understands the emotions, specifically fear and anxiety. In essence, he suggested that fear is the memory of pain, and its adaptive advantage is that it enables individuals to anticipate and avoid injury. Fear-as-memory could be acquired either through individual experience (learned fear) or through species experience (instinctive fear). Among other things, this conception of pain and fear explained why surgical shock (from physical injury) and nervous shock (induced by fear or fright) appeared, at times, to provoke a similar physiologic response--a phenomenon first commented on by the British surgeon, Herbert Page. With this simple grammar, injury-pain-fear, Page and Crile laid the foundations for the modern concept of psychogenic trauma, extending the old idea of "trauma," meaning a wound or physical injury, to include psychological experiences and processes. The modern conception was completed by Freud, by connecting one more emotional state, anxiety. If fear is not simply a memory of pain but a memory that is bound to stimuli in the here-and-now, then anxiety is memory set loose. Put in other words, anxiety is the capacity to imagine pain and not merely to recollect pain. From the time of Beyond the Pleasure Principle (1919), anxiety took on a life of its own, so to speak, no longer part of the constellation of emotions and experiences identified by Page and Crile. Without an external object toward which to direct itself, fear becomes anxiety--a state of nervous anticipation of the unknown, of what is hidden in the shadows or penumbra of awareness. Anxiety is not a vector directed toward a threatening object or event in the environment but is situated in the person's own bodily experience, the workings of the mind, the Cartesian theater of self-representation. As an experience and event located entirely within the psyche, to be mastered by asserting a strong ego, reflections on anxiety became one of the self-constituting experiences of the Western concept of the person. In contemporary psychiatry, the constellation of injury, pain, fear, anxiety, memory, and imagination would seem to live on mainly in the context of traumatogenic anxiety and PTSD.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1994

Applied physiology of strength and power in old age.

The loss of strength and power in old age has important implications for health. Even with healthy elderly people, cross-sectional comparisons imply a loss of strength at some 1.5% per year and of power at some 3.5% per year (averaged across the age range 65 to 84). On the other hand, healthy, very elderly people are at least as responsive to strength-training as younger adults. It is important to establish whether elderly people derive functional benefit from training-induced improvements in strength and whether laboratory measurements of strength and power might be used to identify those elderly people most at risk of losing important, everyday functional abilities.

Activities of Daily Living↗
PubMed1994

Immersion and perfusion staining with 2,3,5-triphenyltetrazolium chloride (TTC) compared to mitochondrial enzymes 6 hours after MCA-occlusion in primates.

2,3,5-triphenyltetrazolium chloride (TTC) is commonly applied in rodents and cats as a marker of infarcted tissue as early as 20 min after the onset of focal ischaemia. At this stage it is suggested that it reflects hypoperfusion rather than failure of respiratory chain. Immersion of brain slices in TTC solution is preferable in comparison to perfusion with TTC in order to ensure, that enough TTC enters the post-occlusion tissue. We compared immersion technique versus perfusion technique 6 h after permanent occlusion of the left middle cerebral artery in 18 baboons. In addition, we assessed the function of the respiratory chain enzymes of stained and unstained tissue in three baboons. The immersion technique revealed an absence of TTC staining limited to subcortical structures in two animals. In seven experiments TTC indicated involvement of almost the entire MCA territory. The extent of the ischaemic lesion indicated by the perfusion technique was very similar. Tissue samples from the presumed infarcted areas revealed normal mitochondrial function. We conclude that perfusion and immersion technique do not cause significant different ischaemic delineation 6 h after middle cerebral artery occlusion. TTC staining appears to be a reliable method of evaluating volume of infarction in primates. Furthermore, absence of TTC staining 6 h after stroke onset is caused by energy or oxygen depletion rather than by mitochondrial injury.

Animals↗
PubMed1994

Exercise studies with elderly volunteers.

The practicalities of conducting exercise studies with elderly and very elderly people have not been well described. In order to help others plan and perform such studies we describe our experience of recruiting volunteers, applying selection criteria, measuring strength, power, cardiorespiratory responses, and potentially related functional abilities. Exclusion criteria are offered, for safety and to characterize subjects as free of disease which might alter their exercise performance. International agreement on these, or similar, criteria would be valuable. The budget must be adequate for prolonged recruitment before a study and for the liberal use of taxis during it. With healthy subjects in their seventies, the coefficients of variation (CV) for repeated measurements of strength and power were: handgrip 3%, isometric knee extension 6%, isometric elbow flexion 6%, and lower limb extensor power 9%. CV for isometric knee extension by healthy subjects in their eighties was 4%. Treadmill ergometry is more time-consuming than with younger subjects. During progressive treadmill tests, the heart rate interpolated to oxygen consumptions of 10 and 15 ml.kg-1.min-1 had CV = 4% and 7%, respectively.

Aged↗
PubMed1994

Strength, power and related functional ability of healthy people aged 65-89 years.

This cross-sectional study was designed to examine the effects of healthy ageing on muscle strength, power, and potentially related functional ability. Subjects were recruited through local and national newspapers and inclusion was based on strict health criteria, by questionnaire. Isometric knee extensor, isometric elbow flexor and handgrip strength, leg extensor power, timed rise from a low chair, lifting a weighted bag on to a surface, and stepping unaided on to boxes of different heights were measured in 50 men and 50 women, evenly distributed over the age range 65-89 years. The differences in isometric strength and leg extensor power over the age range were equivalent to 'losses' of 1-2% per annum and approximately 3 1/2% per annum, respectively. The decline of explosive power was faster than the decline of knee extensor strength in men (p = 0.0001), but not significantly so in women (p = 0.08). Power standardized for body weight influenced chair rise time and step height. Isometric knee extensor strength standardized for body weight influenced chair rise time.

Aged↗
PubMed1994

Symptom attribution in cultural perspective.

The explanatory model perspective of medical anthropology emphasizes the cultural shaping of individuals' efforts to make sense of their symptoms and suffering. Causal attribution is a pivotal cognitive process in this personal and social construction of meaning. Cultural variations in symptom attribution affect the pathogenesis, course, clinical presentation and outcome of psychiatric disorders. Research suggests that styles of attribution for common somatic symptoms may influence patients' tendency to somatize or psychologize psychiatric disorders in primary care. At the same time, symptom attributions are used to negotiate the sociomoral implications of illness. Recent work in social psychology and medical anthropology emphasizes the roots of attributional processes in bodily and social processes that are highly context-dependent, and hence, must be understood as part of the construction of a local world of meaning. Symptom attributions then may be understood as forms of positioning with both cognitive and social consequences relevant to psychiatric assessment and intervention.

Anthropology, Cultural↗
PubMed1994

[Continuing hospice care of cancer--a three-year experience].

The hospice at Mackay Memorial Hospital was established in February 1990. A group of team workers including physicians, nurses, social workers and the clergy were involved in this holistic care program for terminal cancer patients. Four hundred and seventy-nine patients were eligible for the program up to February 1993. Regarding duration of stay, 62.5% of patients resided for 14 days. Those surviving under 90 days constituted 75.5% of patients. Fifty-one point eight percent of patients died in the hospice and 18.2% died at home soon after being discharged from the hospice. Pain is the most common symptom among the patients. Treatment strategies vary according to the three-step-ladder protocol designed by WHO. Total pain relief was achieved in 80% of patients. Opportune private talking and family conferences formed the basis of the "peer model". Through this model, treatment decisions including physical, psychosocial and spiritual issues were made. Before the peer model, only 36 (10.3%) patients agreed with the idea of hospice care, while 257 (73.6%) patients agreed after the model was established. Awareness of dying was evident in 412 (86%) patients. Two hundred and eighty (68%) patients became aware of the prospect of death through guessing, while the other 132 (32%) patients were informed by medical staff. Problems encountered by the team workers included 1) needs in education and training, 2) psychological pressure, 3) management of loss and grief, 4) needs in supportive system and 5) troubles caused by families' lying to patients. The team workers were satisfied with the quality of care in 38.4% of patients and fairly satisfied with 30.7% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗